2 * SPDX-License-Identifier: BSD-2-Clause-NetBSD
4 * Copyright (c) 1998 The NetBSD Foundation, Inc.
5 * Copyright (c) 2014, 2018 Andrey V. Elsukov <ae@FreeBSD.org>
8 * This code is derived from software contributed to The NetBSD Foundation
9 * by Heiko W.Rupp <hwr@pilhuhn.de>
11 * IPv6-over-GRE contributed by Gert Doering <gert@greenie.muc.de>
13 * Redistribution and use in source and binary forms, with or without
14 * modification, are permitted provided that the following conditions
16 * 1. Redistributions of source code must retain the above copyright
17 * notice, this list of conditions and the following disclaimer.
18 * 2. Redistributions in binary form must reproduce the above copyright
19 * notice, this list of conditions and the following disclaimer in the
20 * documentation and/or other materials provided with the distribution.
22 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
23 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
24 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
25 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
26 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
27 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
28 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
29 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
30 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
31 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
32 * POSSIBILITY OF SUCH DAMAGE.
34 * $NetBSD: ip_gre.c,v 1.29 2003/09/05 23:02:43 itojun Exp $
37 #include <sys/cdefs.h>
38 __FBSDID("$FreeBSD$");
41 #include "opt_inet6.h"
43 #include <sys/param.h>
45 #include <sys/systm.h>
46 #include <sys/socket.h>
47 #include <sys/sockio.h>
49 #include <sys/errno.h>
50 #include <sys/kernel.h>
51 #include <sys/sysctl.h>
52 #include <sys/malloc.h>
56 #include <net/if_var.h>
59 #include <netinet/in.h>
60 #include <netinet/in_var.h>
61 #include <netinet/ip.h>
62 #include <netinet/ip_encap.h>
63 #include <netinet/ip_var.h>
66 #include <netinet/ip6.h>
69 #include <net/if_gre.h>
72 VNET_DEFINE(int, ip_gre_ttl) = GRE_TTL;
73 #define V_ip_gre_ttl VNET(ip_gre_ttl)
74 SYSCTL_INT(_net_inet_ip, OID_AUTO, grettl, CTLFLAG_VNET | CTLFLAG_RW,
75 &VNET_NAME(ip_gre_ttl), 0, "Default TTL value for encapsulated packets");
77 VNET_DEFINE_STATIC(struct gre_list *, ipv4_hashtbl) = NULL;
78 VNET_DEFINE_STATIC(struct gre_list *, ipv4_srchashtbl) = NULL;
79 #define V_ipv4_hashtbl VNET(ipv4_hashtbl)
80 #define V_ipv4_srchashtbl VNET(ipv4_srchashtbl)
81 #define GRE_HASH(src, dst) (V_ipv4_hashtbl[\
82 in_gre_hashval((src), (dst)) & (GRE_HASH_SIZE - 1)])
83 #define GRE_SRCHASH(src) (V_ipv4_srchashtbl[\
84 fnv_32_buf(&(src), sizeof(src), FNV1_32_INIT) & (GRE_HASH_SIZE - 1)])
85 #define GRE_HASH_SC(sc) GRE_HASH((sc)->gre_oip.ip_src.s_addr,\
86 (sc)->gre_oip.ip_dst.s_addr)
89 in_gre_hashval(in_addr_t src, in_addr_t dst)
93 ret = fnv_32_buf(&src, sizeof(src), FNV1_32_INIT);
94 return (fnv_32_buf(&dst, sizeof(dst), ret));
98 in_gre_checkdup(const struct gre_softc *sc, in_addr_t src, in_addr_t dst)
100 struct gre_softc *tmp;
102 if (sc->gre_family == AF_INET &&
103 sc->gre_oip.ip_src.s_addr == src &&
104 sc->gre_oip.ip_dst.s_addr == dst)
107 CK_LIST_FOREACH(tmp, &GRE_HASH(src, dst), chain) {
110 if (tmp->gre_oip.ip_src.s_addr == src &&
111 tmp->gre_oip.ip_dst.s_addr == dst)
112 return (EADDRNOTAVAIL);
118 in_gre_lookup(const struct mbuf *m, int off, int proto, void **arg)
121 struct gre_softc *sc;
123 if (V_ipv4_hashtbl == NULL)
126 MPASS(in_epoch(net_epoch_preempt));
127 ip = mtod(m, const struct ip *);
128 CK_LIST_FOREACH(sc, &GRE_HASH(ip->ip_dst.s_addr,
129 ip->ip_src.s_addr), chain) {
131 * This is an inbound packet, its ip_dst is source address
134 if (sc->gre_oip.ip_src.s_addr == ip->ip_dst.s_addr &&
135 sc->gre_oip.ip_dst.s_addr == ip->ip_src.s_addr) {
136 if ((GRE2IFP(sc)->if_flags & IFF_UP) == 0)
139 return (ENCAP_DRV_LOOKUP);
146 * Check that ingress address belongs to local host.
149 in_gre_set_running(struct gre_softc *sc)
152 if (in_localip(sc->gre_oip.ip_src))
153 GRE2IFP(sc)->if_drv_flags |= IFF_DRV_RUNNING;
155 GRE2IFP(sc)->if_drv_flags &= ~IFF_DRV_RUNNING;
159 * ifaddr_event handler.
160 * Clear IFF_DRV_RUNNING flag when ingress address disappears to prevent
161 * source address spoofing.
164 in_gre_srcaddr(void *arg __unused, const struct sockaddr *sa,
167 const struct sockaddr_in *sin;
168 struct gre_softc *sc;
170 if (V_ipv4_srchashtbl == NULL)
173 MPASS(in_epoch(net_epoch_preempt));
174 sin = (const struct sockaddr_in *)sa;
175 CK_LIST_FOREACH(sc, &GRE_SRCHASH(sin->sin_addr.s_addr), srchash) {
176 if (sc->gre_oip.ip_src.s_addr != sin->sin_addr.s_addr)
178 in_gre_set_running(sc);
183 in_gre_attach(struct gre_softc *sc)
186 sc->gre_hlen = sizeof(struct greip);
187 sc->gre_oip.ip_v = IPVERSION;
188 sc->gre_oip.ip_hl = sizeof(struct ip) >> 2;
189 sc->gre_oip.ip_p = IPPROTO_GRE;
190 gre_updatehdr(sc, &sc->gre_gihdr->gi_gre);
191 CK_LIST_INSERT_HEAD(&GRE_HASH_SC(sc), sc, chain);
192 CK_LIST_INSERT_HEAD(&GRE_SRCHASH(sc->gre_oip.ip_src.s_addr),
197 in_gre_setopts(struct gre_softc *sc, u_long cmd, uint32_t value)
200 MPASS(cmd == GRESKEY || cmd == GRESOPTS);
202 /* NOTE: we are protected with gre_ioctl_sx lock */
203 MPASS(sc->gre_family == AF_INET);
204 CK_LIST_REMOVE(sc, chain);
205 CK_LIST_REMOVE(sc, srchash);
210 sc->gre_options = value;
215 in_gre_ioctl(struct gre_softc *sc, u_long cmd, caddr_t data)
217 struct ifreq *ifr = (struct ifreq *)data;
218 struct sockaddr_in *dst, *src;
222 /* NOTE: we are protected with gre_ioctl_sx lock */
226 src = &((struct in_aliasreq *)data)->ifra_addr;
227 dst = &((struct in_aliasreq *)data)->ifra_dstaddr;
230 if (src->sin_family != dst->sin_family ||
231 src->sin_family != AF_INET ||
232 src->sin_len != dst->sin_len ||
233 src->sin_len != sizeof(*src))
235 if (src->sin_addr.s_addr == INADDR_ANY ||
236 dst->sin_addr.s_addr == INADDR_ANY) {
237 error = EADDRNOTAVAIL;
240 if (V_ipv4_hashtbl == NULL) {
241 V_ipv4_hashtbl = gre_hashinit();
242 V_ipv4_srchashtbl = gre_hashinit();
244 error = in_gre_checkdup(sc, src->sin_addr.s_addr,
245 dst->sin_addr.s_addr);
246 if (error == EADDRNOTAVAIL)
248 if (error == EEXIST) {
249 /* Addresses are the same. Just return. */
253 ip = malloc(sizeof(struct greip) + 3 * sizeof(uint32_t),
254 M_GRE, M_WAITOK | M_ZERO);
255 ip->ip_src.s_addr = src->sin_addr.s_addr;
256 ip->ip_dst.s_addr = dst->sin_addr.s_addr;
257 if (sc->gre_family != 0) {
258 /* Detach existing tunnel first */
259 CK_LIST_REMOVE(sc, chain);
260 CK_LIST_REMOVE(sc, srchash);
262 free(sc->gre_hdr, M_GRE);
263 /* XXX: should we notify about link state change? */
265 sc->gre_family = AF_INET;
268 sc->gre_iseq = UINT32_MAX;
270 in_gre_set_running(sc);
272 case SIOCGIFPSRCADDR:
273 case SIOCGIFPDSTADDR:
274 if (sc->gre_family != AF_INET) {
275 error = EADDRNOTAVAIL;
278 src = (struct sockaddr_in *)&ifr->ifr_addr;
279 memset(src, 0, sizeof(*src));
280 src->sin_family = AF_INET;
281 src->sin_len = sizeof(*src);
282 src->sin_addr = (cmd == SIOCGIFPSRCADDR) ?
283 sc->gre_oip.ip_src: sc->gre_oip.ip_dst;
284 error = prison_if(curthread->td_ucred, (struct sockaddr *)src);
286 memset(src, 0, sizeof(*src));
293 in_gre_output(struct mbuf *m, int af, int hlen)
297 gi = mtod(m, struct greip *);
301 * gre_transmit() has used M_PREPEND() that doesn't guarantee
302 * m_data is contiguous more than hlen bytes. Use m_copydata()
303 * here to avoid m_pullup().
305 m_copydata(m, hlen + offsetof(struct ip, ip_tos),
306 sizeof(u_char), &gi->gi_ip.ip_tos);
307 m_copydata(m, hlen + offsetof(struct ip, ip_id),
308 sizeof(u_short), (caddr_t)&gi->gi_ip.ip_id);
312 gi->gi_ip.ip_tos = 0; /* XXX */
313 ip_fillid(&gi->gi_ip);
317 gi->gi_ip.ip_ttl = V_ip_gre_ttl;
318 gi->gi_ip.ip_len = htons(m->m_pkthdr.len);
319 return (ip_output(m, NULL, NULL, IP_FORWARDING, NULL, NULL));
322 static const struct srcaddrtab *ipv4_srcaddrtab = NULL;
323 static const struct encaptab *ecookie = NULL;
324 static const struct encap_config ipv4_encap_cfg = {
325 .proto = IPPROTO_GRE,
326 .min_length = sizeof(struct greip) + sizeof(struct ip),
327 .exact_match = ENCAP_DRV_LOOKUP,
328 .lookup = in_gre_lookup,
336 if (!IS_DEFAULT_VNET(curvnet))
338 ipv4_srcaddrtab = ip_encap_register_srcaddr(in_gre_srcaddr,
340 ecookie = ip_encap_attach(&ipv4_encap_cfg, NULL, M_WAITOK);
347 if (IS_DEFAULT_VNET(curvnet)) {
348 ip_encap_detach(ecookie);
349 ip_encap_unregister_srcaddr(ipv4_srcaddrtab);
351 if (V_ipv4_hashtbl != NULL) {
352 gre_hashdestroy(V_ipv4_hashtbl);
353 gre_hashdestroy(V_ipv4_srchashtbl);